Traditional communication network architectures generally include network architectures of 2G, 3G, and IP Multimedia Subsystem (IMS), and FIG. 1 illustrates a schematic diagram showing the structure of a typical IMS network architecture consisted of various functional resource network elements, generally including a Public Switched Telephone Network (PSTN), a Call Session Control Function (CSCF), a Media Gateway Control Function (MGCF), a Multimedia Resource Function Controller (MRFC), a Multimedia Resource Function Processor (MRFP), a Subscription Locator Function (SLF), a Breakout Gateway Control Function (BGCF), an Application Server (AS), a Home Subscriber Server (HSS), and a User Equipment (UE). Various resource network elements in an existing network may be roughly divided into several categories. For example, the resource network elements in the existing network may be divided into three categories of User Equipments, access devices and control-layer devices by using a certain categorization approach, and the respective categories of resource network elements have their own respective functions and can process specific types of services.
However, the inventors of the invention find that the existing network is disadvantageous at least in that: resources can not be shared between different categories of resource network elements in terms of utilizing the resources, for example, an idle HSS has no way to share its idle resources with an overloaded CSCF in operation; moreover, resources can not be shared even between resource network elements of the same category, for example, a CSCF in Beijing and another CSCF in Shanghai can not share any resource with each other in the existing network architecture. In other words, an overloaded resource network element in operation upon reception of a service request can neither process the service request immediately nor process the service request through another resource network element capable of performing such a function. Consequently, there exists such a phenomenon in which a service can not be processed in time although some network element is idle, which may result in a rather low overall utilization ratio of network resources.